Late Ordovician brachiopods from eastern North Greenland: equatorial offshore migration of the Red River fauna

Abstract: Late Ordovician rhynchonelliformean brachiopods, typical of the North American Red River fauna, are found sporadically in the Børglum River Formation of the Centrum Sø area, Kronprins Christian Land, eastern North Greenland. The geographical distribution of this characteristic brachiopod fauna is thus extended to the easternmost extremity of the Laurentian craton. The assemblage compares specifically with the Hiscobeccus brachiopod fauna, based on key taxa such as notably Hiscobeccus gigas (Wang, 1949), and indicates a late Katian age for this part of the succession. For the first time, this typically inland, shallow‐water fauna is found associated with genera like Bimuria, suggesting a transitional marginal facies with outer shelf benthos. The current study describes a Hiscobeccus fauna that lived at the seaward edge of its preferred habitat. Furthermore, an unpublished Hiscobeccus fauna, from the Børglum River Formation of Peary Land, central North Greenland, as well as several occurrences from the Kap Jackson and Cape Calhoun formations in various parts of Washington Land, western North Greenland, are described here. These show a distinct shift from older strata containing H. capax (Conrad, 1842) to younger strata exclusively yielding specimens of H. gigas. As H. gigas occurs in the upper part of the Cape Calhoun Formation in Washington Land, it indicates that the upper boundary of the Cape Calhoun Formation is considerably younger than previous estimates, reaching into the uppermost Katian (middle Cautleyan–Rawtheyan). The Cape Calhoun Formation correlates with the upper member of the Børglum River Formation and further demonstrates that the Hiscobeccus fauna was widespread in Laurentian marginal settings of North Greenland. Even though the Hiscobeccus fauna was pan‐continental during the late Katian (Richmondian), it possesses a strong provincial signal during the later Ordovician. The new occurrences indicate that this fauna extended to the north‐eastern margin of the Laurentian Craton. It lived in close association with cosmopolitan faunal elements that may have been the earliest sign of the succeeding invasion of migrants from Baltica that arrived later during the Hirnantian. The offshore migration of this atypical Hiscobeccus fauna likely demonstrates the path of warm‐water currents as the Centrum Sø locality was located at the equator during the Late Ordovician.     

ADAPTATION FROM RESTRICTED GEOMETRIES: THE SHELL INCLINATION OF TERRESTRIAL GASTROPODS

The adaptations that occur for support and protection can be studied with regard to the optimal structure that balances these objectives with any imposed constraints. The shell inclination of terrestrial gastropods is an appropriate model to address this problem. In this study, we examined how gastropods improve shell angles to well‐balanced ones from geometrically constrained shapes. Our geometric analysis and physical analysis showed that constantly coiled shells are constrained from adopting a well‐balanced angle; the shell angle of such basic shells tends to increase as the spire index (shell height/width) increases, although the optimum angle for stability is 90° for flat shells and 0° for tall shells. Furthermore, we estimated the influences of the geometric rule and the functional demands on actual shells by measuring the shell angles of both resting and active snails. We found that terrestrial gastropods have shell angles that are suited for balance. The growth lines of the shells indicated that this adaptation depends on the deflection of the last whorl: the apertures of flat shells are deflected downward, whereas those of tall shells are deflected upward. Our observations of active snails demonstrated that the animals hold their shells at better balanced angles than inactive snails.     

On the importance of taking into account agricultural practices when defining conservation priorities for regional planning

Conserving biodiversity in managed landscapes requires the definition of spatial conservation priorities. The systematic conservation planning tools which are used to define these conservation priorities, assess the vulnerability of different locations by combining two different elements: some measurement of the biological assets in question, and some measurement of the key processes which threaten these biological assets. For instance, in cumulative impact mapping, maps of individual human activities that impact ecosystems (hereafter referred to as ‘stressor’ for individual maps and ‘cumulative stressor’ for combined maps) are overlaid with maps of ecosystem vulnerability, in order to estimate the overall ecological impact of human activities on natural ecosystems. These tools are appealing because they are easy to use and inform regional land planning. However, given that once these spatial conservation priorities are defined they potentially have far-reaching consequences, there is a need to test their robustness and reliability. Here we propose to investigate how the uncertainties related to the estimation of a cumulative stressor layer affect the definition of spatial conservation priorities. We conduct a sensitivity analysis of the different ways of estimating major stressors related to human activities (transport, urbanization and population) with a specific focus on agriculture. We show that spatial conservation priorities are little sensitive to most of the parameters and input data used to estimate the cumulative stressor map. In particular, they are not very sensitive to changes in spatially overlapping stressors, i.e. those which overlap spatially with other stressors. However, our analyses also reveal that spatial conservation priorities are highly sensitive to how the agriculture stressor is defined. These results highlight the importance of better understanding how agricultural activities impact biodiversity and establishing how more accurate information on agricultural practices can be used to define spatial conservation priorities.     

Effects of environmental factors on genetic diversity of Caragana microphylla in Horqin Sandy Land,northeast China

Caragana microphylla (Leguminosae) is a dominant climax semishrub species in northern China. We evaluated genetic variation within and among populations sampled from three different environmental gradients in Horqin Sandy Land in northern China using intersimple sequence repeats markers and investigated the possible existence of relationships between genetic diversity and environmental factors. The results showed that C. microphylla have high genetic diversity, and environmental gradients affected genetic diversity of C. microphylla populations. Genetic diversity of all populations was affected by many environmental factors and as well correlated with warm index and soil Olsen phosphorus (SOP) concentration. These results have important implications for restoration and management of these degraded ecosystems in arid and semi‐arid areas.     

Optimal conservation planning of multiple hydrological ecosystem services under land use and climate changes in Teshio river watershed,northernmost of Japan

Most anthropogenic activities impacted on water quality and quantity, and further impacted on ecosystem services (ESs) in watershed are related to land use and climate changes those may cause losses of ecosystem functions. Effective information regarding ESs and their optimal priority conservation planning responded to land use and climate changes provide useful support for diverse stakeholders in ESs planning, management and policies. This study integrated the approach of spatially explicit ESs (water yield, inorganic nutrient, organic nutrient and sediment retentions) by using hydrology and material flow model (Soil and Water Assessment Tools, SWAT model) into systematic conservation of hydrological ESs according to land use and climate changes in Teshio watershed located in the north of Hokkaido, Japan. We investigated the spatial patterns and the hotspots of ESs changes to determine the spatial pattern of changes in systematic conservation optimal area of ES protection in terms of ESs protection targets. Under the land use and climate change scenarios, the forest land use significantly affected on the water yield, sediment, organic-Nitrogen (N) and organic-Phosphorous (P) retentions. The agricultural land (paddy and farmland fields) impacted on the inorganic-N and inorganic-P retentions. We applied the systematic conservation model (MARXAN model) to optimize the area for management of hydrological ESs satisfied the protection targets (30% and 50% of potential maximum ESs values among all scenarios) in all and individual ecosystem services, respectively. The simulated results indicated that the areas of spatial optimal ESs protection for all hydrological ESs were totally different from those for individual ESs. For bundles of ESs, the optimal priority conservation areas concentrated in southwest, north, and southeast of this watershed, which are related to land use, topography and climate driving factors. These places could guarantee ESs sustainability from both environmental protection and agricultural development standpoints. The priority conservation area turned more compact under climate change because the increased precipitation and temperature increased ESs amount. For individual ESs, the optimal priority conservation areas of water yield, sediment retention and organic nutrient retention were traded off against those of inorganic nutrient retention (lower Jaccard's indexes and negative correlations of selection times). Especially, the negative correlation of selection times increased as the conservation target increased from 30% to 50%. The proposed approach provided useful information for assessing the responses of ESs and systematic conservation optimal planning to the land use and climate changes. The systematic conservation optimal areas of hydrological ESs provided an effective trade-off tool between environmental protection (sediment and organic nutrient retentions) and economic development (water yield and inorganic nutrient retention).     

气候波动和土地覆盖变化对广东省植被净初级生产力的相对影响

为深入理解人类活动对陆地生态系统的影响,采用CASA(Carnegie-Ames-Stanford Approach)模型估算广东省2000、2005和2010年实际植被净初级生产力(Net primary productivity,NPP),并基于情景模拟法估算气候和土地覆盖类型稳定条件下的植被NPP,对气候波动和土地覆盖变化在植被NPP变化中的相对贡献进行了研究。结果表明:太阳辐射对植被NPP具有显著的正向控制作用,气温与植被NPP表现为显著负相关,降水不是该区域植被生长的限制性因子;各气候因子与植被NPP的相关性具有季节和区域差异性。在气候不变条件下,土地覆盖变化整体上增加了NPP,对NPP变化的相对贡献与城市扩张格局相类似,不同生态区存在差异性,以珠三角区的贡献最大。总之,气候波动对NPP变化的相对贡献较为复杂,取决于气候因子的波动特征以及与NPP的相关性;其它因子(城市热岛、农耕活动和园林管理等)对NPP变化的相对贡献存在很多不确定性,整体上增加了NPP。     

基于遥感技术的城市下垫面参数与热环境关系的研究——以北京市朝阳区为例

城市热岛（UHI）不仅直接关系到城市人居环境质量和居民健康状况,同时还对城市能源消耗、生态系统过程演变、生物物候以及城市经济可持续发展有着深远的影响。以北京市朝阳区2002—2017年夏季4期Landsat系列遥感影像为数据,采用大气反演法,对15年间朝阳区城市地表温度（LST）时空变化进行分析,发现15年间朝阳区城市热岛比例指数上升迅速,热岛效应逐年加剧。进一步研究表明,城市地表温度与归一化植被指数（NDVI）及归一化建筑指数（NDBI）密切相关：地表温度与NDBI正相关,NDBI指数每升高0.1,地表升温0.79~2.37°C;与NDVI指数负相关,NDVI指数每提高0.1,地表降温0.4~0.77°C。本研究可为城市规划建设与城市绿地营建提供科学具体的参考指导依据,并促进生态可持续发展与人居环境改善。     

Identifying key factors,actors and relevant scales in landscape and conservation planning,management and decision making: Promoting effective citizen involvement

The paper analyses the current limitations of the constraints of decision and action processes in land-use, resource management and conservation policies and approaches, identifying their main factors, proposing alternative strategies to solve the present gaps and limitations. It identifies the need for a new paradigmatic approach based on innovative forms of involvement, commitment and individual and community rewarding systems. This approach is developed based on the characterization of the main drivers of land-use, resource management and conservation policies, namely α-perceptions (immediate and primary satisfaction) and k-perceptions (more mediate and complex consideration of satisfaction, implying long-term perceptions and collective benefits beyond the individual interests). It also analyses the effects of the introduction of new forms of income and incentives (such as trade-offs and payments for environmental services) or management approaches such as Ecological-Based Management or the use of Nature-Based Solutions. The main axioms and instruments necessary to build such a new paradigmatic approach (namely trade-offs, accountability and contractualization) are described. On this basis, it is possible to present a concept for an innovative institutional and social culture and a governance system aimed at an effective land-use, resource management and conservation policies. This governance concept is described and its sustaining individual, social and institutional drivers enunciated.     

Landscape structural analysis of the Lençóis Maranhenses national park: implications for conservation

Our work evaluated the anthropic effects on the landscape structure of the Lençóis Maranhenses National Park (LMNP) and its Buffer Zone, and proposed strategies for the region’s conservation. LMNP is an important protected area in Brazilian north coast which protects a unique wetland ecosystem composed of sand dunes fields and a coastal vegetation called restinga. Supervised mapping of LMNP and a surrounding buffer of 3 km was carried out through high resolution and fine scale (1:5000) satellite images. The mapped area was subdivided in 1000 ha hexagonal Analysis Units (AU) and the following landscape metrics were calculated for each one of them: cover area (CA) of each soil cover class - dune fields (CA-DUNES), water bodies (CA-WATER), dense restinga (CADENSE), scattered restinga (CA-SCATTER), grassland (CA-SANDY), mangroves (CA-MANG), anthropogenic activity (CA-ANTRO) and, secondary vegetation (CA-SECOND); Landscape Shannon Diversity Index (SHDI), and; percentage of native vegetation cover (NV−COV). Pearson correlations were performed between the CA of each class and SHDI to identify the classes most correlated to CA-ANTRO. Our results showed that anthropic classes (crops, trails, and villages) had a stronger correlation (Pearson Correlation, r ≈ 0.65) with phytophysiognomies of dense restinga, secondary vegetation and SHDI, thus indicating that the land use conversion occurs in dense restinga areas and promotes vegetation secondarization, as well as increasing fragmentation. At least, 42% of the dense restinga habitats was destroyed due to human activities. Five conservation and restoration strategies were proposed in a local scale depending on the percentage of native vegetation cover on each AU, from the most to less conserved: (a) only conservation; (b) conservation with management; (c) management; (d) management and restoration; and, (e) restoration. The implementation of Agroforestry Systems with agro-successional restoration goals was recommended as an alternative for land use.     

科尔沁沙地优势固沙灌木叶片氮磷化学计量内稳性

为科学认识科尔沁沙地优势固沙灌木的生态适应性和固沙植被演变规律, 该研究对科尔沁沙地流动沙丘、半固定沙丘、固定沙丘和丘间低地的优势固沙灌木小叶锦鸡儿(Caragana microphylla)和盐蒿(Artemisia halodendron)进行野外调查, 研究了这两种固沙灌木的叶片氮(N)、磷(P)化学计量特征、灌丛土壤养分状况以及内稳性特征。结果表明: 1)与盐蒿相比, 灌木小叶锦鸡儿具有较高的叶片N含量及N:P, 而P含量仅为盐蒿的1/2; 2)两种优势固沙灌木灌丛下土壤的全N、全P含量及速效N、速效P含量高于该地区土壤的平均水平, 小叶锦鸡儿灌丛下土壤养分含量显著高于盐蒿灌丛下土壤; 3)盐蒿叶片N、P化学计量内稳性指数(H)表现为H_P > H_N:P > H_N, 说明盐蒿更易受土壤N的限制; 小叶锦鸡儿叶片N、P化学计量内稳性指数表现为H_N:P > H_N > H_P, 意味着小叶锦鸡儿更易受土壤P的限制。在N含量较低的沙化草地, H_N较高的固沙灌木小叶锦鸡儿比盐蒿更具生长优势, 对于该地区生态恢复及保护具有不可替代的作用。然而, 小叶锦鸡儿额外吸收的N, 使其生长过程可能易受P的限制, 因此在沙地恢复过程中应注意土壤P的供应。